I have been using Easy YouTube Video Downloader for over a year, and except for the few times that there were delays due to YouTube changing its scripting, EYVD has been superb. I use EYVD to download music to listen to before I buy the artists' CDs. EYVD has saved me hundreds of dollars by my discarding the music that was not as good as I originally thought. For me, EYVD is one of the only three add-ons that I use in Firefox. Update June 18, 2022: EYTD continues growing more important for me. Thank you Dishita for this addon!